SYNTHESIS OF SILICON BASED NANOSTRUCTURES FOR BIOMIMICKING AND BIOMEDICAL APPLICATIONS

Abstract

Recently a new field of nanotechnology for biomedical and biomimicking applications has emerged due to advancements in nanofabrication. Such applications require nanostructure fabrication over large area and with low cost. Here, we present two methods to fabricate Si nanostructures: The first employs a lithography-less and highly scalable, bottom-up approach of glancing angle deposition of metal nanoparticles followed by metal assisted chemical etching (MACE) to fabricate vertical Si nanowire arrays. The second uses a top-down approach of interference lithography and MACE to fabricate regular, periodic nanostructures with different cross-sectional shapes. Structural characterization of the nanowires revealed insights into the etching phenomenon. Three applications of the nanostructured surfaces are presented: for (i) modulation of cellular behavior (ii) application in DNA/protein microarray and (iii) superhydrophobic surfaces with tunable adhesion and wettability. We demonstrate the synthesis of low-adhesion and high-adhesion superhydrophobic domains on one substrate and its application to create hierarchical structures.